Heat exchange unit for radial type engines



Oct, 23, 1945. F. M. YOUNG ET AL HEAT EXCHANGE UNIT FOR RADIAL TYPE ENGINES Filed Aug. 28, 1943 3 Sheets-Sheet 1 Get. 23, 1945.

F. M. YOUNG ET AL HEAT EXCHANGE UNIT FOR RADIAL TYPE ENGINES Filed Aug. 28, 1943 3 Sheets-Sheet 2 Get. 23, 145.

F. YOUNG ETAL HEAT EXCHANGE UNIT FOR RADIAL TYPE ENGINES Filed Aug. 28, 1943 3 Sheets-Sheet 3 Patented ct. 23, 1945 HEAT EXCHANGE UNI lT FOR RADIAL TE ENGINES Fred M. Young, Joe C. Shaw, and Howard F. Brinen, Racine, Wis, assignors to Young Radiator Company, a corporation ofWisconsin I Application August 28, istaseriai No. 5003a, B

1 Claim. (01. zstiz) This invention relates to heat exchange units especially adapted for use with the lubricating oil cooling system for radial, aircraft-type engines where employed as the power unit for tanks.

Fig. 1 is a simplified outline elevation oi fa tank showing the li nterior division thereof into crew and power compartments, and indicating the position of the power unit in the latter compartment; Fig. 2 is a diagrammatic view indicating the More particularly the invention relates to a heat 5 general form of this improved. type of heat exexchange unit designed for use with the oiling change unit and its relationship to a radial air- \system for Diesel aircraft-type engine. craft-type engine;

The modern tank must of necessity be a stand- Fig. 3 is an enlarged fragmentary view, partly ardized construction. Moreover, it must be so in section and partly in elevation, of the inlet end arranged that the fullest possible utilization may of one'of the arcuate sections which make up this be made of the space therein. Obviously, as much improved heat exchange unit; 1 l of that space as can be made available is required Fig. 4 is a face view of one of the baliie plates for the crew. That means that the sp ce for a which separates the several tubular core units of power-propelling unit must be restrict d to the which the completed heat exchange unit is commost practical limits consistent with securing the prised; required amount of power to make the operation a Fig. 5 is likewise an enlarged view, partly secof the tank most effective. At the present time, tional and partly elevational, of the valvethe Diesel radial engine best meets this power reequipped coupling which connects the outlet ends quirement. It is much superior and more' ecoof the two arcuate sections which form this imnomical than the gasoline type of radial aircraft- 0 proved type of heat exchange unit; engine. However, the heat dispersion for the Figs. 6 and '7 are enlarged, fragmentary, crosslubricating system of a Diesel engine is many sectional views (Fig. 7. being taken on the line times greater than the heat dispersion of a gaso- 1-7 of Fig. 6) showing how a perimetric band on v line engine of the same type and power. Accordthe tubular units not only reinforces the bonding ingly, the ,cooling system for the lubricating oil of tubes but also serves to space-the perimetric generally provided for the gasoline engine is not tubes away from the supporting housing a bit suitable for use with the Diesel engine. more than would be the case if such a perimetric The main objects of this invention, therefore, band were not used; and' I are to provide an improved construction for a Fig. 8 is across-sectional view taken on the line 1? heat exchange unit'for use with the olling sys- 8-8 of Fig. 2 showing one of the supporting f tem for radial aircraft-type engines as applied to brackets and related flange by" which the unit is tanks; to provide an improved construction of a secured to its supporting frame.

- heat exchange unit as will efiect the heatdisp'er- The outline view of the tank (Fig. 1) indicates slon required for a Diesel radial aircraft-type that a bulkhead 9 divides the interior of the tank engine when applied to tanks of standardized into a crew compartment l0 and a power comconstruction; to provide an improved heat exvpartment II. As previously emphasized, it is imchange unit for this purpose which can be assoperative that the bulkhead 9 be so positioned as ciated with the engine and an air circulat' g unit to provide the fullest possible amount of space in such compact relationship that the ass ciation for the crew compartment Ill. Obviously, this of the parts may be accommodated wi "n the 40 means the restricting of the power unit compartspace heretofore allotted for the tank po er unit; ment to the very minimum consistent with the to provide a heat exchange unit of this type havrequirements for a suitable power unit. I ing an improved arrangement of the warm-up For economic manufacture these tanks must chamber in connection with the main cooling core be of a standardized construction. Heretofore, so as to permit the use of the maximum number this construction has been designed with a view of air-flow ibes within a given space; and to to providing a power compartment I! such as provide an improved heat exchange unit of this would accomodate a radial aircraft-type engine type the economic and .facile manufacture of using gasoline for its fuel. More recent developwhich is made possible by the. assembly of a pluments have sought to. make these tanks more rality of identically-formed, standardized subefiective and economicai'in operation by the use cooling units within a standardized supporting of Diesel-type radial aircraft engines. Naturally, frame. y it has been required to confine the Diesel engine 3 In the embodiment of the invention shown in and all ofits related parts within the power comthe accompanying drawings: partment ll previously arranged for the gasoline type of engine. However, the Diesel engine rev'ide for communication quires a heat dispersion some seven or eight times greater than the heat dispersion required for the gasoline engine. Accordingly, it has been imperative to devise a cooling system for the lubricating oil required for a Diesel engine which would successfully efiect this excessive heat dispersion and at the same time permit the association of the heat exchange unit with the Diesel engine within the tank space allotted for the power unit.

This end has been accomplished by the new and novel structure shown in the drawings. In the embodiment illustrated the cooling unit I2 is in the form of an annulus constructed for coaxial mounting with the engine l3 forward of the engine-cooling fan 14 and for suitable connection to an oil supply tank l5.

The cooling unit as herein shown comprises two arcuate-shaped sections, each of which includes a supporting frame or housing wherein are associated a number of individual tube units IS. A warming chamber or muff I1 is formed on the inner periphery of each of these sections and the two ends of these arcuate sections are connected together b a valve-controlled coupling I8, and related to a piping system through which the flow of oil under the action of the several pumps P is controlled by a thermostatically-operated valve mechanism 19. In its assembled form the cooling unit is attached to a frame supported on the engine l3, forwardly of the fan 44, as shown in dotted outline in Fig. 1.

With the cooling unit thus positioned, the fan l4 draws outside air through the grille 20 and through the tubes of the cooling unit, forces it across the finned portions of the engine and discharges it through a grille 2| in the rear of the tank casing. Incidentally, the bulkhead 9 is provided with suitable openings through which a small amount of air may be drawn from the crew compartment Ill sufficient to keep that compartment free from gases or excessive heat.

'I'he frame or housing for each of the arcuate sections of the cooling unit comprises a pair of concentrically arranged plates 22 and 23 held together in the spaced relationship by the silversoldered baflie plates 24, thereby forming several compartments for the tubular cooling units IS. The upper and lower ends of these concentrically arranged plates are closed by chambered castings 25 and 25A respectively.

The baflle plates are formed with main open- 26 and orifices 21. The main openings probetween the cores of adings jac'ent tube units l6. tioned that the openings 26 in adjacent plates are located at the opposite peripheries of the housing and thus require the oil to follow a circuitous path as it travels the length of each of the arcuate sections, as has been indicated by I the arrows in Figs. 2 and 3. The small orifices 21 allow for a direct seepage from the core of one tubular unit IE to the other at the ends of the baffle plate opposite where occurs the main flow of oil from one core section to the other.

The individual cooling units l6 are each made up of a bundle of tubes, the ends of which are expanded into hexagonal heads 29. These heads contact each other so as to hold the cylindrical portion of the tubes 28 in spaced relationship whereby, when the hexagonal heads 29 are bondedtogether, the space around these tubes becomes a sealed core for the circulation of oil. Each unit [6 is made up individually but on a standard pattern so that any unit will fit within any one of the divisions between adjacent battle The plates are so posi-' 2) and have outlets 43 (Fig. 3) communicating hexagonal heads of the respective rows of tubes.

Opposite these enlarged spaces in the core the plate 23 has orifices providing communication with the warm-up chamber or mufi 11. Such a radial enlargement of the oil core communicating with the warm-up chamber helps to facilitate the flow of oil through the cooling unit, when the use of the cooling system is initiated in low temperatures, as will hereinafter more fully appear.

A narrow band 3| is formed around the opposite perimeters of each of the tubular units l6, as shown in Figs. 6 and '7. Not only do these bands provide reinforcing bonds around the unit, but they also serve to space the perimetric rows of tubes slightly further away from the housing than would be the case otherwise. This also helps to facilitate the flow of oil through the cooling system when it is first put into use in low temperatures.

The warm-up chamber or mufi I1 is formed by securing a U-shaped channel member to the inner periphery of the plate 23 and having its ends secured to the end castings25 and 25A.

As most clearly shown in Fig. 5, the coupling i8 unites the two arcuate sections through its connection to the castings 25 by means of suitable cap screws. This coupling I8 is formed with a pair of chambers 33 and 34 communication between which is controlled by a valve 35, actuated by a thermostat 36, for the purpose of directing the flow of oil from the two sections of the heat outlet 31.

The chambers 33 and 34 are formed by a Partition 38 having a valve-seat opening 39 connecting said chambers. The chamber 33 connects with the outlet 31 and a passage 40 in each of the castings 25 which in turn communicate with the; cores of adjacent tubular units 16. The chamber 34 connects with a passage 4| in each of the castings 25 which in turn communicate with the adjacent ends of the warm-up chamber or muff H.

The thermostat 36 may be of any type sufficiently sensitive to the temperature of the oil in the chamber 33 to shift the valve 35 into and out of coactive relationship with the valve-seat opening 39. As herein shown, the thermostat is of a bellows type which employs a highly volatile liquid as the motive agent. However, a thermostat using as its motive agent a wax composition with a high coefficient of expansion would be equally suitable.

The castings 25A have suitable inlets 42 (Fig.

with the interior which in turn communicate with the oil core of the adjacent tubular units I6 and outlets 44 communicating with the warm-up chamber or muff l1. Orifices 45 provide a small supplemental communication between the interior of the castings 25A and the core of the adjacent tubular unit 16.

This heat exchange unit I2 is mounted on a exchange unit through the common.

frame supported on the engine l3 co-axially therewith. The attachment is made by means of flanged U-shaped brackets 46 (Fig. 8) which are secured to the outer face of the plate 22 and the muff IT. A flange 41 on each of these brackets is suitably apertured for receiving bolts whereby to secure the unit in place on the supporting frame. A special form of the bracket 46A is provided for the end castings 25A.

The valve mechanism I9 is a surge-valve type similar to that shown in copending application of Joe C. Shaw, Ser. No. 510,869 filed November 19, 1943. It is formed and equipped with a thermostatically-controlled valve so that when the temperature of the oil is below a critical point it would by-pass the heat exchange unit l2 altogether being directed from pipe leading from the supply tank Hi to the engine l3. When the temperature of the oil rose above this critical temperature, the valve mechanism l9 would be shifted by the thermostat to permit the oil to flowthrough the pipes connected with the inlets 43 of the two arcuate sections of the heat exchange unit l2.

The operation of the heat exchange unit herein shown, when connected with a Diesel engine in a tank, is as follows:

The flow of oil through the heat exchange unit is effected by means of the pumps P arranged in a system of pipes connecting the engine I3 and oil supply tank IS with the heat exchange unit I2 During normal operation, the oil passing through the core of the two arcuate sections is exposed to heat exchange contact with the air drawn through the tubes and the temperature of the oil effected accordingly.

If under certain weather conditions the tank has been standing idle, the temperature of the oil in the system may be so cold and its viscosity consequently so high as to preclude the advisability of attempting to move the oil through the heat exchange unit l2. In such case the valve mechanism I9 would function to cause the oil to by-pass the unit l2, simply moving through the pipe system between the supply tank l5 and enine l3. Under less severe weather conditions the oil may be sufliciently viscous to pass through the warm-up chamber or muff I! but not through the main core of the arcuate sections. Under such conditions the valve mechanism will be actuated to permit the delivery of oil to the heat exchange unit inlets 38. However, the thermostat 36 will have acted to retract the valve 35 to open communication between the chambers 33 and 34 and with the common outlet 31. This will permit the oil to how from the warm-up chamber or mufi I! through the passages 4| of the castings 25 into the chamber 34, through the chamber 33, and out through the common outlet 31.

The oil being circulated through the piping system between the engine and the oil supply tank tends to rise in temperature. This warmer oil passing along the warm-up chamber or muiT I! communicates heat to oil in the contiguous area of the core of the tubular units I6. Moreover, the oil begins to trickle in throu h the orifices 32 into the communicating enlarged core areas in units l6. Also some of this warming oil muff will attempt toenter the core of the units I8 next adjacent to the castings 25A.

This warmer oil trickling into the units l8 will gradually reduce the viscosity of the oil in the cores and thereby further increase the temperature of the oil preparatory to securing a normal flow through the arcuate sections.

As the temperature of the oil passing through the chamber 33 begins to rise, the thermostat 36 will act to move the valve 35 to gradually cut off the flow of oil through the opening 39 between the compartments 33 and 34. As soon as this temperature rise is sufiicient to cause the thermostat 36 to completely close the opening 39, a back pressure through the warm-up chamber or I! will be established. Thereupon the pressure of the pumps P will require the oil to flow through the core of the arcuate sections of the heat exchange unit, following the circuitous path indicated by the arrows in Fig. 2 and passing out through the outlet 31.

Variations and modifications in the details of structure and arrangement of the parts may be resorted to within the spirit and coverage of the appended claim:

We claim:

An annulus-type heat exchange unit comprising, two arcuate-shaped sections each formed of a pair of concentrically-arranged plates held together in spaced relationship by radially-disposed bafiles, bundles of closely-spaced, axiallydisposed tubes inserted between said plates and said baflies and at their ends suitably bonded together and to said plates and battles to form a sealed core surrounding said tubes extending the full circumferential length of said sections, said baiiies having openings formed therein permitting communication between the cores of adjacent tube bundles, the openings in successive =baiiies being placed adjacent opposite plates whereby the now of the coolant through said arcuate sections is radially crosswise as well as circumferential, a U-shaped member secured to the outer face of one of the said concentric plates of each of said sections and constituting an auxiliary chamber axially and circumferentially coextensive with the sealed core part thereof, cap members interfltting with said plates and U-shaped members to close the opposite ends of each of the cores and auxiliary chambers formed thereby, each of said cap members having separate ports communicating respectively with the adjacent ends of said core and auxiliary chamber, a two-chamber coupling connecting two contiguous cap members with said chambers communicating respectively with the separate ports in said caps, a valve seat in the partition separating said coupling chambers, a thermostatically-actuated valve mechanism adapted to coact with said valve seat to control communication between said chambers so as to determine the path of the coolant through said core and auxiliary chamber, and coolant inlet means connected to the cap members at the opposite ends of said arcuate-shaped sections.

FRED M. YOUNG.

JOE C. SHAW.

HOWARD F. B .l' l 

